Janos, I thought you were serious that the v8 was a relevant example in this conversation. I will not continue to discuss obsurd examples. Let's all keep this conversation productive.
Stephen
If the two Acuras had the same horsepower rating, the answer is obvious - they should be on the same spec line, i.e., just like the RX8. And I'd note that you seem to be conceding that the only reason for having two spec lines is that they have two different HP ratings, not that there is any real difference in the cars otherwise.
But since they don't, ycu could go either way. You can either do one spec line at the higher power and weight, or do the two as you did, with two weights. Which route you should take may be specific to the particular car. If it would be almost impossible to meet the lower weight, you might as well just have a single spec line at the higher weight. If the lower HP version is much more readily available, that might be a good reason to have two spec lines. The primary argument in favor of two spec lines is that it doesn't make it almost mandatory that you run the higher HP version. So unless you can't meet the lower weight, or the higher HP version is far more available and thus the version everyone will want to run anyway, two spec lines would be what I'd vote for in this case. Particularly if some people have already built the lighter version. (But if the HP were the same, one spec line is obvious.)
One question, how does a 10 HP difference equate to a 200# increase? I thought the ITS multiplier was around 14 lb/hp, not 20.
On a separate note, since you keep bringing up the S4 vs S5 RX7, do you plan to add the S4 RX7 at ~2400 pounds?
Tom Lyttle
Decatur, GA
IT7 Mazda - 2006, 2008 SARRC Champion
ITS Nissan 200SX - finally running correctly
FP Ford Capri - waiting for a comp adjustment
GT3 Dodge Daytona - what was I thinking?
Come on Josh, you are either willfully playing ignorant or you are not the Mazda guru I was told you were when on the ITAC. Or are you that Josh?? If not disregard.
Either way you are playing games to the obsurd to make it look like a big deal. The Renesis in the 09 is the same casting with an M8 hole tapped in the housing for another oil injection port. Every other part in the short block is identical to the 04-08. You are most likely aware that all rotaries are allowed to mix oil in the fuel so these are not necessary for a race motor. This is no different than your V8 comparison where a given block might have a slightly different boss cast in for a given accessory. Bore, stroke, pistons, cam, valves, etc are all the same. Irrelevant to the performance or function of the motor. Other difference is the secondary fuel rail on the intake, which has 2 less injectors. But then you already know that but think it is fun to keep playing these games and shoving the weight deal in our face. You think it's fun to shove the weight thing in our face. (Repeated for emphasis)
Steve Eckerich
ITS 18 Speedsource RX7
ITR RX8 (under construction)
No. that would undo a lot of what has been done for years, and we try to avoid that. doesn't mean we want to do it again, though. the question is when does merging lines become a problem, and when does keeping them separate become likewise.
re: the 200#, it's 10*1.25*12.9*.945(FWD) or 150
200*1.25*12.9*0.945 = 3050
210*1.25*12.9*0.945 = 3200
looks like we made a boo-boo in the weight of the 02-04 car. will fix. oh, and from an IT perspective, a cam swap with 05-06 cams will make the engines identical (from what I have learned, there may be other details) in the eyes of the process and for all other IT-relevant intents and purposes.
Last edited by Chip42; 02-26-2014 at 05:40 PM.
Depending on the differences Chip, would you not look at classing like the Miata that had 2 seperate HP ratings and just class them all with the higher number. Would need to see what the Honda guys wanted, but long run it would be a much better deal if no other changes caused adders in the process. I would think many might opt for the lower HP number and the lighter weight. Of course they might do that and just use the cam too.
Steve Eckerich
ITS 18 Speedsource RX7
ITR RX8 (under construction)
Again, speaking in the abstract and to general policies rather than the RX8 as a case study, there's a flip side to this coin: If the update/backdate options on a spec line create a de facto situation where a particular mix-and-match option has an advantage (a la the ITS 2nd gen RX7 "kit"), it's going to be an expensive proposition to turn any of the year/trim level choices into the "right" model that never existed in the wild.... To UD/BD a car to a different spec line would cost thousands of dollars, even if all the parts are just cosmetic bolt on parts. Please DO NOT go in this direction.
K
Kirk could you please list the "kit" you speak of that makes an ITS RX7 greater than the best listed model?
The GTUS was the aluminum hood, non sunroof, 89-91 spec motor with the good brakes that everything from 89 on had. Have I missed something all these years?
Steve Eckerich
ITS 18 Speedsource RX7
ITR RX8 (under construction)
Which is a long way to go to say they aren't the same engine. They are very similar, but not the same. If a piston engine had a block head combo with different water channels, would you say they were the same engine? I wouldn't.
It's got a very similar engine and there is a history of sometimes keeping such cars on the same line.
Which is it? The car is over weight or not? Because if the RX8 is the overweight pig it is claimed to be and there is no difference between the 08 and the 09, the 09 will be the same over weight pig as the rest of them. How in the hell is listing it on the same spec line going to make a damn bit of difference? Hey! My 08 isn't competitive, so I'll build a car out of this more expensive 09 tub that is identical to the 08! That's the ticket!But then you already know that but think it is fun to keep playing these games and shoving the weight deal in our face. You think it's fun to shove the weight thing in our face. (Repeated for emphasis)
I'm all in favor of getting it through the process correctly, but drop the sob story about the legions of RX8 owners spending time on the cross if this goes on a new line.
What you seem to have is a car with a similar motor (which by itself doesn't justify a spec line change), a different unibody (and there's plenty of evidence that minor production line changes don't justify a new line) and different "suspension geometry" which IMO, if it mounts to new points, is the big problem putting it on one line.
And I'm not Josh or even Joshing.
Got ya, So you really have no basis in fact or real knowledge about the cars. Guys that post with no signature get that. Carry on.
Haven't heard a word from any of us about the weight since it was set at #2850, not great, but the car is well balanced and should race well with others in the class. Get over yourself on the cross anology, history just proves if it does not get done in the beginning, it never will. See ITB.
Steve Eckerich
ITS 18 Speedsource RX7
ITR RX8 (under construction)
I understood that there was a particular year (or years) of FI/induction that was thought to be optimal in there too, Steve, but you'd know better than I would.
Point being, if I start with an '87 like Mazda gave us back in the ESCORT days, I have to spend some coin to optimize it.
K
You are correct there Kirk, years ago when they were newer it was more. Basically all it took to make the early cars even with the 89-91 cars was the later motor combination. Later bumper looks better, but that was about it. I have early cars that came with the aluminum hood, but the .756 fifth gear was not until 89. That is why all the RX7's were run through the process at the max numbers for the 89-91 setup.
The myth that the update/backdate on the RX7 made a car that was better than any single model built is not true. Everything we consider the best parts for a build were on one single model. That we can use an 86-88 shell to get there is the part I have been pushing here. Thats all. No different with the RX8, the 09 is a better car because the weak links were engineered out like any other car reaching the end of a model run. Nobody is playing games, we were very clear in the beginning of this thread that the later parts are better engineered for the car and handle a race beating better.
Please be honest, did you ever find information I gave you in the original classing of this car to be false? Were the dyno sheets I gave the ITAC not as high or higher than anyone else has claimed?
Steve Eckerich
ITS 18 Speedsource RX7
ITR RX8 (under construction)
You keep ignoring the part where I say that I agree with you on the RX8, Steve - at least based on what's been shared here.
K
Good one! If Mazda hadn't put another bore home in the 2009 and you just did it yourself, would you say the engine in your 2008 was IT legal? No, because it ain't the same motor. Or let's say they made a GFY01 that used the new motor and left the 08 version in the 09 RX8... Still think you could slap the new motor in the RX8? No, because it ain't the same motor.
I've asked this several times... Please explain how a bunch of folks who won't build the 08 and earlier car would be willing to build the identical car if it was an 09. #pretendimfrommissouri
John, Joe, Josh, Jim, Janos, Jamie, who ever you are... READ the thread.
RELIABLE TRANSMISSION. Is that simple enough?
Stephen Blethen.
People are building the old car, but they want to be able to use the updated reliable parts, such as the tranny. Personally I think the car can be very capable in ITR, I don't believe a 2009 can be any faster then an 2008 , but it will be cheaper to run. For me it's just the transmission.
Last edited by kevin22; 02-27-2014 at 07:36 AM.
Kevin Anderson
Chris Carey
Central Florida Region
ITS/Vintage Datsun 240Z
Favorite tool to remove undercoating---- A curb!
"Understeer is when you hit the wall with the front of the car and oversteer is when you hit the wall with the rear of the car.
Horsepower is how fast you hit the wall, torque is how far you take the wall with you."
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